The printer is printing multiple labels.
This condition is often caused by dusty/dirty media sensors in the Zebra printer. These sensors are located in the bar that flips up at the entry end of the printer (see the diagram below). There is a small red light that shines through the label & backing and detects the gap between the labels as it shines through with more intensity in the gap. Clean those sensors well with an alcohol wipe. Align the one in the bar so that it is about in the center of the label so it can consistently measure the gap as it passes through. Reinstall the label media and make sure it aligns against the back inside of the printer and runs through the knurled roller on the bottom. Make sure all guides and sensors are in the right position and close the three points to clamp the labels in place. Calibrate the label position using the Print Engine calibration process. Test for a while in normal operation to verify that the issue has been resolved.
